1. Field of the Invention
The present invention relates to the field of transport technology, as is used, in particular, within print finishing. It relates to a crossing between two transport lines, according to the preamble to claim 1.
2. Discussion of Related Art
In print finishing, also know as print further processing, but not just in this sphere, planar articles, for example folded printed sheets, newspapers, brochures, flyers or the like, are frequently transported in compressed form as an imbricated stream between the various treatment and/or storage stations. It is here often necessary to divert imbricated streams from one transport line to another, intersecting transport line, this diversion being intended to be realized by switchable means. In a first setting, the articles are forwarded on one transport line without further obstacle. In a switchable second setting, the imbricated stream is diverted from one transport line to the intersecting other transport line. The imbricated stream formation as such is here intended to remain as far as possible unchanged.
Printed publication DE 33 02 935 discloses an apparatus for turning partial imbricated streams of given length, consisting of printed sheets or the like, about their vertical centre axis, in which printed sheets in the form of an imbricated stream are directed via a right-angled diverter to a points switch, and from this onto a winding station belt. The printed sheets are spooled with a winding tape onto a core to form a reel and are temporarily stored in this form. If the printed sheets are to be fed to the finishing facility, then the winding tape is unrolled from the reel and rolled back on from a tape supply roll. As the winding tape is unrolled from the reel, a points switch is pivoted into a lower position, whereby the printed sheets make their way onto a lower, right-angled diverter, and from this onto a part of a conveying line (see FIGS. 1 and 2 of this publication). The diversion between the individual lines is here realized by fixed 90° deflectors, the free ends of which are arranged one above the other and can be freely selected by a points switch.
Printed publication DE 33 04 219 discloses an apparatus for stacking printed sheets, having a hub rotatably mounted in a machine stand, having a tape which is led up to the hub along a predefined path and can be spooled onto or Unspooled from this, a first transfer point being provided on the path of the tape. The tape is guided over a plurality of diverting rollers and can selectively be spooled on one of two hubs and forms on its path a first transfer point and a second transfer point. A points switch arrangement connects, on the one hand, the second transfer point to a feeder conveying line and to the first transfer point. It further connects the first transfer point to an evacuation line. The points switch arrangement has a fixedly mounted conveyor belt, which can be driven in two directions, as well as two parallel conveyor belts, whose ends facing one conveyor belt can be swung up and down. If, on the feeder conveyor line, a multiplicity of printed sheets which are joined together into a partial imbricated stream are advanced and the printed sheets are ejected from there onto one conveyor belt, then these printed sheets, once again in the form of a partial imbricated stream, are transferred from the lowered end of the conveyor belt onto the other conveyor belt, and from there onto a further belt (see FIGS. 1-3). In this case, too, the switchable diversion is effected solely by pivotable switch points.
The same also applies to the device for processing print products according to printed publication WO 94/02398.
In all cases known from the prior art, actively driven points switches are used to achieve switchability, whereby a more complex drive mechanism and control system is demanded. Moreover, the imbricated stream formation is frequently changed or influenced.